I read the original post to this topic. Then read the rest of the thread. This sums up my opinion on how you'd get more tanks:

Quote Originally Posted by Giantbane View Post
In my mind there's basically one solution to this. Make an awesome iconic class a tank, and you'll get a bunch of people playing it.

PLD and WAR are kinda vanilla compared to the other currently available jobs, there's a bigger draw to BLM, DRG, SMN, etc ... and that's aside from the general mindset that more people want to play DPS than tanks.

If they were to add Samurai (with katana) or Soldier (Cloud) as tank jobs, I think it would be less of a problem.
The suggestions on how to "fix" GLD/PLD would do nothing. If it's not involved enough for you, try getting all cross-class skills you can have at your disposal for PLD. This involves leveling up CNJ to 34 and MRD to 27. IMHO this makes PLD a bit more interesting to play because it provides you with a handful of new options.

Personally, I really enjoy tanking in this game, especially on WAR. It's more focused on damage reversal combined with heavy hitting than the PLD's straightforward damage mitigation.

The one thing I agree with in the original post, though, is that a lot of pre-endgame leading up to level 50 as PLD makes GLD a very boring class to start out with. Every other class and job is more interesting to play up to endgame. Pre-endgame, I found PLD quite lackluster when compared to WAR.